The site won the 2009 Pulitzer Prize for National Reporting for tracking the veracity of presidential candidates during the 2008 election. The Pulitzer Prize board cited the St. Petersburg Times Staff for “its fact-checking initiative during the 2008 presidential campaign that used probing reporters and the power of the World Wide Web to examine more than 750 political claims, separating rhetoric from truth to enlighten voters.”

After the election, the site was refocused, says Bill Adair, Washington Bureau Chief for the St. Petersburg Times and PolitiFact’s editor. “We re-launched in January and added the Obameter, our database that tracks the status of President Obama's campaign promises,” he says.

The site began checking the truthfulness of pundits’ statements roughly two months ago, Mr. Adair said in an e-mail interview. “We'd gotten many requests from readers to do it, but I resisted because I wanted to stay more focused on elected officials.”

Checking important political players

“After the Democrats started calling Rush the de facto leader of the Republican Party, I realized that we needed to check pundits and talk show hosts, too,” Adair said. “I've come to realize they are every bit as important in the political discourse as elected officials.”

The site responds to fact checking requests from users. And, unlike some parts of the press that shy away from making tough calls, PolitiFact is willing to state that a pundit said something false or barely true – and actually back the statement up with facts, not just bold assertions.

Hyberbole on the right and left

So, for example, Rush Limbaugh was wrong when he said, "You can't read a speech by George Washington . . . without hearing him reference God, the Almighty." In fact, only two out of 13 of Washington’s speeches refer to God, according to PolitiFact research.

And Ms. Maddow was wrong when she said Alaska Gov. Sarah Palin, "got precisely zero support for her call for Alaska's Democratic Senator Mark Begich to resign because Ted Stevens' corruption conviction was overturned." According to PolitiFact research, it wasn't Palin's idea, and she wasn't particularly wedded to it, and others supported it.